I am a 3c/4a and I found that Rusk's Being Wild elongated my curls to near straightness. Maybe that's too much of the elongating effect that you want, but maybe you can use a little less and see what happens. It's a smooth paste like texture. Rusk can be found in Trade Secrets which is often located in malls.
I am a 3c reformed product junkie thanks to the economy.
I lurk a lot, I change my hair color a lot. It's currently black and bsl when wet and beyond my shoulders still when dry.
Now I will stop procrastinating and get back to what I was supposed to be doing before I got on here.